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Technical
Based on their findings, One Eighty recommended several crucial actions for the leaking jacket case:
• Implementation of a quality welding procedure: To ensure proper welds and minimize localized corrosion susceptibility
• Improved post-weld surface treatments: Specifically, thorough pickling and passivation to restore the protective layer
• Water chemistry control: Directly controlling the water chemistry, including pH balance and getting rid of any galvanised components, replacing them with an all-stainless steel closed-loop system, and if not stainless steel, non-reactive polymers for piping.
• Regular water testing at selected intervals: To provide early warnings of system deviations, which can be implemented during maintenance cycles.
De Waal then broadened the discussion to general preventative strategies, drawing from his extensive experience with various heat exchanger failures, including pinhole failures in copper tubing, issues with galvanised spiral coil heat exchangers, and even cracking in other water reservoirs and cooling towers jacketed systems due to unsuitable local water sources.
Key preventative strategies include:
• Consistent water quality monitoring: Ensuring the water used is within the acceptable ranges as specified by the manufacturer.
• Material compatibility checks: Avoiding incompatible material combinations like stainless steel units with galvanised piping or copper tubing in larger systems, especially if water quality is not rigorously monitored
• Selection of corrosion-resistant materials: Choosing materials that are inherently more resistant to the specific corrosive elements present in the water, considering the galvanic series to prevent sacrificial corrosion, which should be implemented in the initial conception and design phase of the plant / facility / heat exchanger itself.
• Implementing regular maintenance programs: This includes proactive water testing, visual inspections, and addressing issues like scale formation or discoloration promptly. RACA
Products
JUST BETTER‘ BEAST’ 12CFM VACUUM PUMP
A large vacuum pump is an essential tool for HVAC & R( Heating, Ventilation, Air Conditioning and Refrigeration) contractors, providing several key benefits:
1. Faster evacuation times
• A large vacuum pump has a higher CFM( cubic feet per minute) rating, allowing contractors to evacuate refrigerant lines and systems much faster than smaller pumps
• This efficiency is crucial when working on large commercial or industrial HVAC systems, where extensive piping requires significant evacuation
2. Deep vacuum capability
• Larger pumps can achieve deeper vacuums, removing moisture and non-condensable gases more effectively
• This ensures proper refrigerant charge, prevents system contamination, and enhances system longevity
3. Improved system performance
• By thoroughly removing air, moisture and contaminants, a deep vacuum helps prevent issues like: o Ice formation inside refrigerant lines o Acid buildup that can corrode components o Poor heat transfer and efficiency losses
4. Handles larger systems with ease
• Large pumps are ideal for commercial and industrial systems, such as chillers, large split systems and rooftop units
• Using a small pump on a large system can take too long or may not achieve the necessary vacuum level
5. Durability and longevity
• Heavy-duty vacuum pumps are built with stronger motors and better cooling mechanisms, ensuring longer operational life and reliability under continuous use
• This is important for contractors who service multiple largescale projects daily
6. Saves labour and increases productivity
• Faster vacuum times mean technicians can complete jobs quicker, reducing labour costs and increasing the number of service calls per day
• Especially beneficial for high-demand summer and winter seasons when HVAC service requests peak
7. Better suitability for high-vacuum applications
• Some systems, like low-temperature refrigeration units and VRF( Variable Refrigerant Flow) systems, require very deep vacuums to operate efficiently
• A larger pump ensures these systems meet manufacturer vacuum requirements
8. Compatibility with large diameter hoses
• Large vacuum pumps work well with larger diameter hoses( such as 3 / 8 " or 1 / 2 "), which further speeds up evacuation times
• This combination improves efficiency over using standard 1 / 4 " hoses
A large vacuum pump is a timesaving, high-efficiency tool that helps HVAC & R contractors work on large systems quickly and effectively, while ensuring proper moisture and contaminant removal. Investing in a quality large vacuum pump increases service speed, system reliability and customer satisfaction.
For additional information, call + 27( 0) 11 620 0300
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RACA Journal I November 2025 www. refrigerationandaircon. co. za